Portable Generator Information

Things to Consider When Purchasing a Portable Generator

Noise: Sound is measured in units called decibels and noted as Db. Decibels are somewhat hard to understand but in simple terms, 70 Db is TWICE as loud as 60 Db. The really noisy generators you hear at your neighbor’s house is probably above 75 Db. When you look at a manufacture’s claim for decibels, you have to know at what distance they are measuring the sound level.

The following YouTube by Honda is pretty good at explaining different sound levels:

Decibel Demonstration by Honda

Basically, any portable generator that is 70 Db or less at 10 ft is considered quiet. The super quiet inverter units will be below 60 Db and you will hardly know they are there. Above 80 Db at 10 ft and you and your neighbors will hate it.

Remember, the larger the generator, the louder it generally is. Buying an over sized generator will generally be buying a noisier generator. Most home owners purchase generators in the 6,000 to 8,000 watt range. (See Generator Size section) Over Head Valve (OHV) engines are quieter than the old valve in block design but most generators today are OHV. It should be noted that quietness costs money. The super quiet units use an inverter to create the power so the engines can run at slower speeds but inverters are generally limited to 2,500 watts and are very expensive.

Fuel Economy

Many people think “I am not going to use this generator that often so I don’t care about fuel economy”. Remember, it is not just the cost of fuel, you have to go out and get it and in a bad storm, it may be many miles away to find a gas station open. So if your generator burns 8 gallons in 8 hours that is 24 gallons a day; that is 5 – five gallon cans you have to get home each day. If you only have two five gallon cans, that is a minimum of three trips per day. Better fuel economy costs a bit more but generally it is associated with quieter models so the combination is generally worth a 25 to 35% premium over the basic entry level models.

Ease of Mobility

Units with wheels are MUCH easier to move in and out of a shed or garage. Wheel kits are generally available for base price units but are about $20 to $30; money that could be put towards a better generator. Air tires may seem like a premium but remember you have to keep the tires pumped up and people do not always remember to do this once or twice per year. Air tires are really only important if you will have to roll your portable generator through gravel or grass.

Electric Start

Electric start is a great idea if the battery is not dead. It is almost mandatory for generators 9000 watts and above as most people cannot pull the cord hard enough; especially if the generator is kept in a unheated space. If you choose electric start, consider a trickle charger to keep the battery fully charged. Any auto supply sells a trickle charger. Make sure you tell them you only want to keep a battery fresh, not recharge it.

Service

It is a good idea to ask the seller who will provide repair service if you have problems. There are fewer and fewer small engine (lawnmower) repair shops.

Generator Size

This is one of the first questions people ask before they buy a generator. There are many on line calculators but most of these don’t really answer the question. A basic understanding of what power things take to operate and the fact that everything does not have to work at one time will help you pick the smallest generator that will meet your needs. (Smaller generators cost less, are quieter, and burn less fuel.) Remember that with the Interlockkit, you can turn on and off each breaker in your panel so you can keep two or more things from operating at the same time. By looking at the information below you will see that you can do most things like laundry or heat water or cook with a 6000 to 8000 watt generator. If you do overload the unit by turning on too many appliances, the lights will dim and you will know to turn something off. There is a circuit breaker on the generator to keep you from overloading it and damaging the generator.

Light Bulbs – generally the maximum per bulb is 100 watts so 10 lights on at one time is 1000 watts. Use compact florescent bulbs and it will be more like 10 lights equals 300 watts.

Toaster Oven – a full size toaster oven is a maximum of 1800 watts.

Microwave – the most popular over the stove built-in is 1000 watts.

Stovetop Element – single large element for skillet is about 1800 watts.

Water Heater – full size water heater is 4000 watts.

Water Pump – 1 hp is 800 watts – 1.5 hp is 1200 watts.

Hair Dryer – 1500 watts

Clothes Washer – 1800 watts

Electric Clothes Dryer – 5500 watts

Gas or Oil Boiler – 500 watts

Gas or Oil Furnace – 700 watts

Other – all appliance sold in the United States have a nameplate that will tell you the watts used. This is the number of watts you should apply to your generator sizing calculation.

Central AC – It is generally not practical to run a central air conditioner on a normal size portable generator. Normally you would need a 12000 watt or larger generator to start and run a central air conditioner. If you have an air conditioner you would like help deciding what size generator you would need to run, Email us at questions@interlockkit.com with a clear picture of the name plate on the outside unit and we will respond.

Heat Pump – See Air Conditioner above and know that most heat pumps have emergency heat that starts at 10,000 watts and goes up so it is unlikely you will run your heat pump on a portable generator without changing the wiring on the indoor fan unit to keep the emergency heat from coming on.

Generally, a 6000 to 8000 watt generator will keep you comfortable and while you will have to select what you run at the same time, you can run pretty much everything you need accept AC and Heat Pumps. If you have natural gas, oil, or propane heat, you can run your furnace or boiler.

Links to Generator Sites

Generator Interlock Technologies does not sell generators. Any 120/240 volt generator will work with our interlock kits. We offer the below links to major manufacturers to help make comparing you options easier.

Hopefully you are now better equipped to choose the right backup power source for your home in the event of an outage. If you have any questions about our generator installation service, do not hesitate to give Master-Electrical a call!